Rate

110-250

Regularity

Regular

P waves

None

PRI

None

QRS

> 0.12; bizarre

Rate

60-100

Regularity

Irregular

P waves

Upright and uniform

PRI

0.12-0.20

QRS

0.08-0.12

Rate

60-100

Regularity

Regular

P waves

Inverted, if present

PRI

< 0.12, if P waves are even visible

QRS

0.08-0.12